INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) activity.LDL hasbeen proposed as a useful discriminatory vehicle forthe deliv...INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) activity.LDL hasbeen proposed as a useful discriminatory vehicle forthe delivery of cytotoxic drugs to tumor cells.LDL presents many advantages as drug展开更多
Monocyte chemoattractant protein-1(MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capac...Monocyte chemoattractant protein-1(MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capacity of human peripheral blood monocytes to express MCP-1 and effects of native very low density lipoprotein (VLDL) and oxidized VLDL(OX-VLDL) on the expression. The total RNA was extracted from cultured monocytes, which were exposed to VLDL and OX-VLDL, and the media conditioned by monocytes were collected. MCP-1 mRNA expression was examined by Northern blot analysis. MCP-1 protein in conditioned media was determined by using sandwich ELISA. The results showed that monocytes can express MCP-1 after a 24 h incubation at 37℃，and the expression was markedly increased by a exposure to OX-VLDL, whereas the expression was slightly increased when exposed to VLDL. It suggests that the capacity of monocytes to produce MCP-1 that recruits and activates circulating monocytes may be of considerable importance in atherogenesis, and oxidation of VLDL enhances its potential to promote atherogenesis.展开更多
Objective PERK/eI F2α/CHOP is a major signaling pathway mediating endoplasmic reticulum(ER) stress related with atherosclerosis.Oxidized LDL(ox-LDL) also induces endothelial apoptosis and plays a vital role in the in...Objective PERK/eI F2α/CHOP is a major signaling pathway mediating endoplasmic reticulum(ER) stress related with atherosclerosis.Oxidized LDL(ox-LDL) also induces endothelial apoptosis and plays a vital role in the initiation and progression of atherosclerosis.The present study was conducted to explore the regulatory effect of ox-LDL on PERK/e IF2α/CHOP signaling pathway in vascular endothelial cells.Methods The effects of ox-LDL on PERK and p-e IF2α protein expression of primary human umbilical vein endothelial cells(HUVECs) were investigated by Western blot analysis.PERK gene silencing and selective eI F2α phosphatase inhibitor,salubrinal were used to inhibit the process of ox-LDL induced endothelial cell apoptosis,caspase-3 activity,and CHOP mR NA level.Results Ox-LDL treatment significantly increased the expression of PERK,PERK-mediated inactivation of e IF2α phosphorylation,and the expression of CHOP,as well as the caspase-3 activity and apoptosis.The effects of ox-LDL were markedly decreased by knocking down PERK with stable transduction of lentiviral sh RNA or by selective eI F2α phosphatase inhibitor,salubrinal.Conclusion This study provides the first evidence that ox-LDL induces apoptosis in vascular endothelial cells mediated largely via the PERK/eI F2α/CHOP ER-stress pathway.It adds new insights into the molecular mechanisms underlying the pathogenesis and progression of atherosclerosis.展开更多
Objective. To research the relations between low- density lipoprotein receptor- related protein gene (LRP) polymorphism, butyrylcholinesterase gene (BchE) polymorphism and Alzheimer’s disease (AD) in Chinese. Methods...Objective. To research the relations between low- density lipoprotein receptor- related protein gene (LRP) polymorphism, butyrylcholinesterase gene (BchE) polymorphism and Alzheimer’s disease (AD) in Chinese. Methods. The gene polymorphisms of LRP and BchE were genotyped in 38 AD cases and 40 controls with polymerase chain reaction- restriction fragment length polymorphism (PCR- RFLP) methods. AD groups were classified according to the LRP C/C genotype and compared with matched controls. Results. AD group had higher frequencies of C/C homozygote (81.6％ vs 60.0％ , P< 0.05) and of C allele (89.5％ vs 76.3％ , P< 0.05),with no significant difference between any of these LRP genotypes classified AD groups and their respective control groups. Conclusions. A positive correlation was found between LRP gene polymorphism and AD, but not between BchE gene polymorphism and AD in Chinese AD cases.展开更多
Atherosclerotic cardiovascular disease is the main cause of mortality and morbidity in the world.Plasma levels of low density lipoprotein cholesterol(LDL-C) are positively correlated with the risk of atherosclerosis.H...Atherosclerotic cardiovascular disease is the main cause of mortality and morbidity in the world.Plasma levels of low density lipoprotein cholesterol(LDL-C) are positively correlated with the risk of atherosclerosis.High plasma LDL concentrations in patients with hypercholesterolemia lead to build-up of LDL in the inner walls of the arteries,which becomes oxidized and promotes the formation of foam cells,consequently initiating atherosclerosis.Plasma LDL is mainly cleared through the LDL receptor(LDLR) pathway.Mutations in the LDLR cause familiar hypercholesterolemia and increase the risk of premature coronary heart disease.The expression of LDLR is regulated at the transcriptional level via the sterol regulatory element binding protein 2(SREBP-2) and at the posttranslational levels mainly through proprotein convertase subtilisin/kexin-type 9(PCSK9) and inducible degrader of the LDLR(IDOL).In this review,we summarize the latest advances in the studies of PCSK9.展开更多
The effects of oxidized low density lipoprotein (ox-LDL) on the proliferation of cultured human vascular smooth muscle cells (vSMC) were investigated in vitro. By using NaBr density gra-dient centrifugation, LDL was i...The effects of oxidized low density lipoprotein (ox-LDL) on the proliferation of cultured human vascular smooth muscle cells (vSMC) were investigated in vitro. By using NaBr density gra-dient centrifugation, LDL was isolated and purified from human plasma. Ox-LDL was produced from LDL by being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations (35, 60, 85, 110, 135 and 160 μg/mL) for 7 days. The influence of ox-LDL on vSMC proliferation was observed in growth curve, mitosis index, and in situ determination of apoptosis. The data were analyzed with SPSS 10.0 software. The results showed that the ox-LDL produced in vitro had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in athero-sclerotic plaque. ox-LDL at a concentration of 35 μg/mL demonstrated the strongest proliferation in-ducement, and at a concentration of 135 μg/mL, ox-LDL could inhibit the growth of vSMC. ox-LDL at concentrations of 35 and 50 μg/mL presented powerful mitotic trigger, and with the increase of ox-LDL concentration, the mitotic index of vSMC was decreased gradually. ox-LDL at higher con-centrations promoted more apoptotic vSMCs. ox-LDL at lower concentrations triggered proliferation of vSMCs, and at higher concentrations induced apoptosis in vSMCs. ox-LDL played a promotional role in the pathogenesis and development of atherosclerosis by affecting vSMC proliferation and apoptosis.展开更多
A modified chitosan adsorbent was synthesized through a simple preparation procedure, and it demonstrated good adsorption performance for selective removal of low density lipoprotein in human plasma. Phase inversion t...A modified chitosan adsorbent was synthesized through a simple preparation procedure, and it demonstrated good adsorption performance for selective removal of low density lipoprotein in human plasma. Phase inversion technique was employed to form chitosan beads, to which epoxy groups were then introduced by reacting with ethyleneglycol diglycidylether, and tryptophan was subsequently coupled to the epoxy-activated beads.展开更多
Aim:The oxidized low-density lipoprotein(OxLDL) plays an important role in atherosclerosis yet it remains unclear if it damages circulating erythrocytes. Method: In this study。
AIM: To investigate how hepatitis C virus(HCV) G1 b infection influences the particle number of lipoproteins.METHODS: The numbers of lipoprotein particles in fasting sera from 173 Japanese subjects, 82 with active HCV...AIM: To investigate how hepatitis C virus(HCV) G1 b infection influences the particle number of lipoproteins.METHODS: The numbers of lipoprotein particles in fasting sera from 173 Japanese subjects, 82 with active HCV G1 b infection(active HCV group) and 91 with cleared HCV infection(SVR group), were examined. Serum lipoprotein was fractionated by high-performance liquid chromatography into twenty fractions. The cholesterol and triglyceride concentrations in each fraction were measured using Lipo SEARCH. The number of lipoprotein particles in each fraction was calculated using a newly developed algorithm, and the relationship between chronic HCV G1 b infection and the lipoprotein particle number was determined by multiple linear regression analysis.RESULTS: The median number of low-density lipoprotein(LDL) particles was significantly lower in the active HCV group [1182 nmol/L, interquartile range(IQR): 444 nmol/L] than in the SVR group(1363 nmol/L, IQR: 472 nmol/L, P < 0.001), as was that of highdensity lipoprotein(HDL) particles(14168 nmol/L vs 15054 nmol/L, IQR: 4114 nmol/L vs 3385 nmol/L, P = 0.042). The number of very low-density lipoprotein(VLDL) particles was similar between the two groups. Among the four LDL sub-fractions, the number of large LDL particles was similar between the two groups. However, the numbers of medium(median: 533.0 nmol/L, IQR: 214.7 nmol/L vs median: 633.5 nmol/L, IQR: 229.6 nmol/L, P < 0.001), small(median: 190.9 nmol/L, IQR: 152.4 nmol/L vs median: 263.2 nmol/L, IQR: 159.9 nmol/L; P < 0.001), and very small LDL particles(median: 103.5 nmol/L, IQR: 66.8 nmol/L vs median: 139.3 nmol/L, IQR: 67.3 nmol/L, P < 0.001) were significantly lower in the active HCV group than in the SVR group, respectively. Multiple linear regression analysis indicated an association between HCV G1 b infection and the decreased numbers of medium, small, and very small LDL particles. However, active HCV infection did not affect the number of large LDL particles or any sub-fractions of VLDL and HDL particles.CONCLUSION: HCV G1 b infection decreases the numbers of medium, small, and very small LDL particles.展开更多
Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibrobl...Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.展开更多
Objective To investigate the association between low-density lipoprotein receptor-related protein 5(LRP5) variants(rs12363572 and rs4930588) and type 2 diabetes mellitus(T2DM) in Han Chinese. Methods A total of 1842 T...Objective To investigate the association between low-density lipoprotein receptor-related protein 5(LRP5) variants(rs12363572 and rs4930588) and type 2 diabetes mellitus(T2DM) in Han Chinese. Methods A total of 1842 T2 DM cases(507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms(SNPs). Odds ratios(ORs) and 95% confidence intervals(95% CIs) were calculated to describe the strength of the association by logistic regression. Results In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2 DM, even after adjusting for relevant covariates. When stratified by body mass index(BMI), the two SNPs were also not associated with T2 DM. Among the 3 common haplotypes, only haplotype TT was associated with reduced risk of T2DM(OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI(P<0.001) and rs4930588 was associated with triglyceride levels(P=0.043) in 507 newly diagnosed T2 DM cases but not in healthy controls. Conclusion No LRP5 variant was found to be associated with T2 DM in Han Chinese, but haplotype TT was found to be associated with T2 DM.展开更多
In order to investigate the roles of Wnt signal pathway in transformation of cardiac valvular myofibroblasts to the osteoblast-like phenotype, the primary cultured porcine aortic valve myofibroblasts were incubated wi...In order to investigate the roles of Wnt signal pathway in transformation of cardiac valvular myofibroblasts to the osteoblast-like phenotype, the primary cultured porcine aortic valve myofibroblasts were incubated with oxidized low density lipoprotein(ox-LDL, 50 mg/L), and divided into four groups according to the ox-LDL treatment time: control group, ox-LDL 24-h group, ox-LDL 48-h group, and ox-LDL 72-h group. Wnt signal pathway blocker Dickkopf-1(DDK-1, 100 μg/L) was added in ox-LDL 72-h group. The expression of α-smooth muscle actin(α-SMA), bone morphogenetic protein 2(BMP2), alkaline phosphatase(ALP), and osteogenic transcription factor Cbfa-1 was detected by Western blotting, and that of β-catenin, a key mediator of Wnt signal pathway by immunocytochemical staining method. The Wnt/β-catenin was observed and the transformation of myofibroblasts to the osteoblast-like phenotype was examined. The expression of α-SMA, BMP2, ALP and Cbfa-1 proteins in the control group was weaker than in the ox-LDL-treated groups. In ox-LDL-treated groups, the protein expression of α-SMA, BMP2, ALP, and Cbfa-1 was significantly increased in a time-dependent manner as compared with the control group, and there was significant difference among the three ox-LDL-treated groups(P<0.05 for all); β-catenin protein was also up-regulated in the ox-LDL-treated groups in a time-dependent manner as compared with the control group(P<0.05), and its transfer from cytoplasm to nucleus and accumulation in the nucleus were increased in the same fashion(P<0.05). After addition of DKK-1, the expression of α-SMA, bone-related proteins and β-catenin protein was significantly reduced as compared with ox-LDL 72-h group(P<0.05). The Wnt/ β-catenin signaling pathway may play an important role in transformation of valvular myofibroblasts to the osteoblast-like phenotype.展开更多
Objective: To investigate the molecular mechanisms and effective target ponits of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) recep...Objective: To investigate the molecular mechanisms and effective target ponits of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) receptors in macrophages in mice. Methods: Macrophages in mice were treated with curcumin, which was purified from the ethanolly extraction of Rhizoma Curcumae Longae for 24 h. The LDL receptors expressed in the macrophages were determined by enzyme-linked immunosorbent assay (ELISA) and assay of DiI labeled LDL uptake by flow cytometer. Results: It was found for the first time that 10 μmol/L-50 μmol/L curcumin could obviously up-regulate the expression of LDL receptor in macrophages in mice, and a dose-effect relationship was demonstrated. Conclusion: One of the lipid-lowering mechanisms of traditional Chinese medicine, Rhizoma Curcumae Longae, was completed by the effect of curcumin through the up-regulation of the expression of LDL receptor.展开更多
A novel low-density lipoprotein adsorbent was prepared simply by directly phosphonating porous cellulose beads. Tests in vitro demonstrated that this adsorbent showed quite good adsorption performance for selective re...A novel low-density lipoprotein adsorbent was prepared simply by directly phosphonating porous cellulose beads. Tests in vitro demonstrated that this adsorbent showed quite good adsorption performance for selective removal of low-density lipoprotein from human plasma. The effects of preparation conditions on the lipoprotein sorption properties of the resulted adsorbent were investigated. The adsorption dynamics was also examined.展开更多
Summary:In the present study, we examined the regulation of the expression and function of ABCA1 by modified LDL (ox-LDL) in vitro. After incubation with apoA-I for 24 h, RAW264.7 cells effluxed 37.65 % cholesterol lo...Summary:In the present study, we examined the regulation of the expression and function of ABCA1 by modified LDL (ox-LDL) in vitro. After incubation with apoA-I for 24 h, RAW264.7 cells effluxed 37.65 % cholesterol loaded by acetyl LDL (ac-LDL), and 9.78 % cholesterol in ox-LDL group. The level of ABCA1 mRNA increased about three times either when cells were incubated with 100 μg /mL ac-LDL or with 100 μg /mL ox-LDL. However, the level of ABCA1 protein rose by 1.57 times in ac-LDL group and 1.26 times in ox-LDL group. These results demonstrated that ox-LDL had different effect on the expression and function of ABCA1, ox-LDL might decrease the cholesterol efflux mediated by ABCA1 through other unknown mechanisms.展开更多
The American Diabetes Association (ADA) 2013 guidelines state that a reasonable hemoglobin A1c goal for many nonpregnant adults with diabetes is less than 7.0% a hemoglobin A1c level of less than 6.5% may be considere...The American Diabetes Association (ADA) 2013 guidelines state that a reasonable hemoglobin A1c goal for many nonpregnant adults with diabetes is less than 7.0% a hemoglobin A1c level of less than 6.5% may be considered in adults with short duration of diabetes, long life expectancy, and no significant cardiovascular disease if this can be achieved without significant hypoglycemia or other adverse effects of treatment. A hemoglobin A1c level less than 8.0% may be appropriate for patients with a history of severe hypoglycemia, limited life expectancy, advanced macrovascular and microvascular complications, extensive comorbidities, and long-standing diabetes in whom the hemoglobin A1c goal is difficult to attain despite multiple glucoselowering drugs including insulin. The ADA 2013 guidelines recommend that the systolic blood pressure in most diabetics with hypertension should be reduced to less than 140 mmHg. These guidelines also recommend use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in the treatment of hypertension in diabetics unless they are pregnant. Diabetics at high risk for cardiovascular events should have theirserum low-density lipoprotein (LDL) cholesterol lowered to less than 70 mg/dL with statins. Lower-risk diabetics should have their serum LDL cholesterol reduced to less than 100 mg/dL. Combination therapy of a statin with either a fibrate or niacin has not been shown to provide additional cardiovascular benefit above statin therapy alone and is not recommended. Hypertriglyceridemia should be treated with dietary and lifestyle changes. Severe hypertriglyceridemia should be treated with drug therapy to reduce the risk of acute pancreatitis.展开更多
To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively...To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively, the ldl-A7 cell lines were transfected and two cell lines expressing VLDL-R were obtained: one stably expressing the VLDLR with the O-linked sugar region (type I VLDLR) and the other without the O-linked sugar region (type II VLDLR). In the study on binding of VLDLR to their nuclein labeled natural ligands (VLDL and β-VLDL), it was found that surface binding of 125I-VLDL or 125I-β-VLDL of ldl-A7 cells transfected with type I VLDLR recombinant (ldl-A7-VRI) was more higher than that of ldl-A7 cells transfected with type II VLDLR recombinant (ldl-A7-VRII). After being incubated with VLDL for different time, the contents of triglyceride and total cholesterol in cells were mensurated, and the formation of foam cells and accumulation of lipid in cells was observed by oil-red O staining. The results showed that the contents of triglyceride and total cholesterol in ldl-A7-VR I were much higher than those in ldl-A7-VR II, and ldl-A7-VR I could transform into foam cells notably. It was suggested that type I VLDLR binds with relative higher affinity to VLDL and β-VLDL, and internalizes much more lipoprotein into cells. As a result, we can conclude that type I VLDLR plays a more important role in lipoprotein metabolism and foam cells formation than type II VLDLR.展开更多
BACKGROUND Cholesterol is related to improvements in the rate of sustained virological response and a robust immune response against the hepatitis C virus(HCV).APOE gene polymorphisms regulate cholesterol levels modif...BACKGROUND Cholesterol is related to improvements in the rate of sustained virological response and a robust immune response against the hepatitis C virus(HCV).APOE gene polymorphisms regulate cholesterol levels modifying the course of the HCV infection.The relationship between cholesterol,APOE alleles,and the outcome of HCV infection has not been evaluated in the admixed population of Mexico.AIM To investigate the role of APOE-ε2,-ε3,and-ε4 alleles and the metabolic profile in the outcome of HCV infection.METHODS A total of 299 treatment-na?ve HCV patients were included in this retrospective study.Patients were stratified in chronic hepatitis C(CHC)(n=206)and spontaneous clearance(SC)(n=93).A clinical record was registered.Biochemical tests were assessed by dry chemistry assay.APOE genotypes were determined using a Real-Time polymerase chain reaction assay.RESULTS Total cholesterol,low-density lipoprotein cholesterol(LDL-c),triglycerides,and hypercholesterolemia were higher in SC than CHC patients as well as the frequency of the APOEε4 allele(12.4%vs 7.3%).SC patients were overweight(54.8%).Theε4 allele was associated with SC(OR=0.55,95%CI:0.31-0.98,P=0.042)and mild fibrosis(F1-F2)in CHC patients(OR 0.091,95%CI 0.01-0.75,P=0.020).LDL-c≥101.5 mg/dL(OR=0.20,95%CI:0.10-0.41,P<0.001)and BMI≥26.6 kg/m2(OR=0.37,95%CI:0.18-0.76,P<0.001)were associated with SC status;while ALT≥50.5 IU/L was negatively associated(OR=5.67,95%CI:2.69-11.97,P<0.001).CONCLUSION In SC patients,the APOEε4 allele and LDL-c conferred a protective effect in the course of the HCV infection in the context of excess body weight.展开更多
基金the Scientific Foundation of Shandong Provincial Scientific & Technical Commission,No.971164607.
文摘INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) activity.LDL hasbeen proposed as a useful discriminatory vehicle forthe delivery of cytotoxic drugs to tumor cells.LDL presents many advantages as drug
文摘Monocyte chemoattractant protein-1(MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capacity of human peripheral blood monocytes to express MCP-1 and effects of native very low density lipoprotein (VLDL) and oxidized VLDL(OX-VLDL) on the expression. The total RNA was extracted from cultured monocytes, which were exposed to VLDL and OX-VLDL, and the media conditioned by monocytes were collected. MCP-1 mRNA expression was examined by Northern blot analysis. MCP-1 protein in conditioned media was determined by using sandwich ELISA. The results showed that monocytes can express MCP-1 after a 24 h incubation at 37℃，and the expression was markedly increased by a exposure to OX-VLDL, whereas the expression was slightly increased when exposed to VLDL. It suggests that the capacity of monocytes to produce MCP-1 that recruits and activates circulating monocytes may be of considerable importance in atherogenesis, and oxidation of VLDL enhances its potential to promote atherogenesis.
基金State Key Clinical Specialty Construction Project,China
文摘Objective PERK/eI F2α/CHOP is a major signaling pathway mediating endoplasmic reticulum(ER) stress related with atherosclerosis.Oxidized LDL(ox-LDL) also induces endothelial apoptosis and plays a vital role in the initiation and progression of atherosclerosis.The present study was conducted to explore the regulatory effect of ox-LDL on PERK/e IF2α/CHOP signaling pathway in vascular endothelial cells.Methods The effects of ox-LDL on PERK and p-e IF2α protein expression of primary human umbilical vein endothelial cells(HUVECs) were investigated by Western blot analysis.PERK gene silencing and selective eI F2α phosphatase inhibitor,salubrinal were used to inhibit the process of ox-LDL induced endothelial cell apoptosis,caspase-3 activity,and CHOP mR NA level.Results Ox-LDL treatment significantly increased the expression of PERK,PERK-mediated inactivation of e IF2α phosphorylation,and the expression of CHOP,as well as the caspase-3 activity and apoptosis.The effects of ox-LDL were markedly decreased by knocking down PERK with stable transduction of lentiviral sh RNA or by selective eI F2α phosphatase inhibitor,salubrinal.Conclusion This study provides the first evidence that ox-LDL induces apoptosis in vascular endothelial cells mediated largely via the PERK/eI F2α/CHOP ER-stress pathway.It adds new insights into the molecular mechanisms underlying the pathogenesis and progression of atherosclerosis.
文摘Objective. To research the relations between low- density lipoprotein receptor- related protein gene (LRP) polymorphism, butyrylcholinesterase gene (BchE) polymorphism and Alzheimer’s disease (AD) in Chinese. Methods. The gene polymorphisms of LRP and BchE were genotyped in 38 AD cases and 40 controls with polymerase chain reaction- restriction fragment length polymorphism (PCR- RFLP) methods. AD groups were classified according to the LRP C/C genotype and compared with matched controls. Results. AD group had higher frequencies of C/C homozygote (81.6％ vs 60.0％ , P< 0.05) and of C allele (89.5％ vs 76.3％ , P< 0.05),with no significant difference between any of these LRP genotypes classified AD groups and their respective control groups. Conclusions. A positive correlation was found between LRP gene polymorphism and AD, but not between BchE gene polymorphism and AD in Chinese AD cases.
基金D.W.Z.is a Scholar of the Alberta Heritage Foundation for Medical Research and is supported in part by a Canadian Institutes of Health Research New Investigator AwardZhang laboratory is supported by Canadian Foundation for Innovation,grants from a Grant-in-Aidfor Heart and Stroke Foundation of CanadaPfizer Canada, the Canadian Institutes of Health Research(MOP 93794), and Mazankowski Alberta Heart Institute
文摘Atherosclerotic cardiovascular disease is the main cause of mortality and morbidity in the world.Plasma levels of low density lipoprotein cholesterol(LDL-C) are positively correlated with the risk of atherosclerosis.High plasma LDL concentrations in patients with hypercholesterolemia lead to build-up of LDL in the inner walls of the arteries,which becomes oxidized and promotes the formation of foam cells,consequently initiating atherosclerosis.Plasma LDL is mainly cleared through the LDL receptor(LDLR) pathway.Mutations in the LDLR cause familiar hypercholesterolemia and increase the risk of premature coronary heart disease.The expression of LDLR is regulated at the transcriptional level via the sterol regulatory element binding protein 2(SREBP-2) and at the posttranslational levels mainly through proprotein convertase subtilisin/kexin-type 9(PCSK9) and inducible degrader of the LDLR(IDOL).In this review,we summarize the latest advances in the studies of PCSK9.
基金This project was supported by a grant from Provincial Outstanding Youth Program for Henan Province Committee of Sciences and Technology (No. 19972002).
文摘The effects of oxidized low density lipoprotein (ox-LDL) on the proliferation of cultured human vascular smooth muscle cells (vSMC) were investigated in vitro. By using NaBr density gra-dient centrifugation, LDL was isolated and purified from human plasma. Ox-LDL was produced from LDL by being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations (35, 60, 85, 110, 135 and 160 μg/mL) for 7 days. The influence of ox-LDL on vSMC proliferation was observed in growth curve, mitosis index, and in situ determination of apoptosis. The data were analyzed with SPSS 10.0 software. The results showed that the ox-LDL produced in vitro had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in athero-sclerotic plaque. ox-LDL at a concentration of 35 μg/mL demonstrated the strongest proliferation in-ducement, and at a concentration of 135 μg/mL, ox-LDL could inhibit the growth of vSMC. ox-LDL at concentrations of 35 and 50 μg/mL presented powerful mitotic trigger, and with the increase of ox-LDL concentration, the mitotic index of vSMC was decreased gradually. ox-LDL at higher con-centrations promoted more apoptotic vSMCs. ox-LDL at lower concentrations triggered proliferation of vSMCs, and at higher concentrations induced apoptosis in vSMCs. ox-LDL played a promotional role in the pathogenesis and development of atherosclerosis by affecting vSMC proliferation and apoptosis.
文摘A modified chitosan adsorbent was synthesized through a simple preparation procedure, and it demonstrated good adsorption performance for selective removal of low density lipoprotein in human plasma. Phase inversion technique was employed to form chitosan beads, to which epoxy groups were then introduced by reacting with ethyleneglycol diglycidylether, and tryptophan was subsequently coupled to the epoxy-activated beads.
基金supported by National Natural Science Foundation of China(NSFC10572159)supported by "111 Project" entitled "Biomechanics&Tissue Repair Engineering"(No.:B06023)Chongqing Science&Technology Council(CSTC 2006ba5010)
文摘Aim:The oxidized low-density lipoprotein(OxLDL) plays an important role in atherosclerosis yet it remains unclear if it damages circulating erythrocytes. Method: In this study。
文摘AIM: To investigate how hepatitis C virus(HCV) G1 b infection influences the particle number of lipoproteins.METHODS: The numbers of lipoprotein particles in fasting sera from 173 Japanese subjects, 82 with active HCV G1 b infection(active HCV group) and 91 with cleared HCV infection(SVR group), were examined. Serum lipoprotein was fractionated by high-performance liquid chromatography into twenty fractions. The cholesterol and triglyceride concentrations in each fraction were measured using Lipo SEARCH. The number of lipoprotein particles in each fraction was calculated using a newly developed algorithm, and the relationship between chronic HCV G1 b infection and the lipoprotein particle number was determined by multiple linear regression analysis.RESULTS: The median number of low-density lipoprotein(LDL) particles was significantly lower in the active HCV group [1182 nmol/L, interquartile range(IQR): 444 nmol/L] than in the SVR group(1363 nmol/L, IQR: 472 nmol/L, P < 0.001), as was that of highdensity lipoprotein(HDL) particles(14168 nmol/L vs 15054 nmol/L, IQR: 4114 nmol/L vs 3385 nmol/L, P = 0.042). The number of very low-density lipoprotein(VLDL) particles was similar between the two groups. Among the four LDL sub-fractions, the number of large LDL particles was similar between the two groups. However, the numbers of medium(median: 533.0 nmol/L, IQR: 214.7 nmol/L vs median: 633.5 nmol/L, IQR: 229.6 nmol/L, P < 0.001), small(median: 190.9 nmol/L, IQR: 152.4 nmol/L vs median: 263.2 nmol/L, IQR: 159.9 nmol/L; P < 0.001), and very small LDL particles(median: 103.5 nmol/L, IQR: 66.8 nmol/L vs median: 139.3 nmol/L, IQR: 67.3 nmol/L, P < 0.001) were significantly lower in the active HCV group than in the SVR group, respectively. Multiple linear regression analysis indicated an association between HCV G1 b infection and the decreased numbers of medium, small, and very small LDL particles. However, active HCV infection did not affect the number of large LDL particles or any sub-fractions of VLDL and HDL particles.CONCLUSION: HCV G1 b infection decreases the numbers of medium, small, and very small LDL particles.
基金the National Natural Science Foundation of China(81372872 to J.Yang,81402215 to X.Du,and 81320108022 to K.Chen)funds from the University Cancer Foundation via the Sister Institution Network Fund at the Tianjin Medical University Cancer Institute and Hospital,Fudan University Shanghai Cancer Center,and University of Texas MD Anderson Cancer Centersupported by the program for Innovative Research Team in University in China(IRT1076 to K.Chen)
文摘Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.
基金supported by the National Natural Science Foundation of China(No.81072359)Natural Science Foundation of Guangdong Province(No.S2013010016791)+1 种基金Science and Technology Development Foundation of Shenzhen(No.JCYJ20120613112221107 and JCYJ20130326110246234)Natural Science Foundation of Shenzhen University(No.801-00035911)
文摘Objective To investigate the association between low-density lipoprotein receptor-related protein 5(LRP5) variants(rs12363572 and rs4930588) and type 2 diabetes mellitus(T2DM) in Han Chinese. Methods A total of 1842 T2 DM cases(507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms(SNPs). Odds ratios(ORs) and 95% confidence intervals(95% CIs) were calculated to describe the strength of the association by logistic regression. Results In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2 DM, even after adjusting for relevant covariates. When stratified by body mass index(BMI), the two SNPs were also not associated with T2 DM. Among the 3 common haplotypes, only haplotype TT was associated with reduced risk of T2DM(OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI(P<0.001) and rs4930588 was associated with triglyceride levels(P=0.043) in 507 newly diagnosed T2 DM cases but not in healthy controls. Conclusion No LRP5 variant was found to be associated with T2 DM in Han Chinese, but haplotype TT was found to be associated with T2 DM.
基金supported by grants from the National Nature Science Foundation of China(No.81070190)the Foundation of Natural Sciences of Hubei Province of China(No.2014CFB962)
文摘In order to investigate the roles of Wnt signal pathway in transformation of cardiac valvular myofibroblasts to the osteoblast-like phenotype, the primary cultured porcine aortic valve myofibroblasts were incubated with oxidized low density lipoprotein(ox-LDL, 50 mg/L), and divided into four groups according to the ox-LDL treatment time: control group, ox-LDL 24-h group, ox-LDL 48-h group, and ox-LDL 72-h group. Wnt signal pathway blocker Dickkopf-1(DDK-1, 100 μg/L) was added in ox-LDL 72-h group. The expression of α-smooth muscle actin(α-SMA), bone morphogenetic protein 2(BMP2), alkaline phosphatase(ALP), and osteogenic transcription factor Cbfa-1 was detected by Western blotting, and that of β-catenin, a key mediator of Wnt signal pathway by immunocytochemical staining method. The Wnt/β-catenin was observed and the transformation of myofibroblasts to the osteoblast-like phenotype was examined. The expression of α-SMA, BMP2, ALP and Cbfa-1 proteins in the control group was weaker than in the ox-LDL-treated groups. In ox-LDL-treated groups, the protein expression of α-SMA, BMP2, ALP, and Cbfa-1 was significantly increased in a time-dependent manner as compared with the control group, and there was significant difference among the three ox-LDL-treated groups(P<0.05 for all); β-catenin protein was also up-regulated in the ox-LDL-treated groups in a time-dependent manner as compared with the control group(P<0.05), and its transfer from cytoplasm to nucleus and accumulation in the nucleus were increased in the same fashion(P<0.05). After addition of DKK-1, the expression of α-SMA, bone-related proteins and β-catenin protein was significantly reduced as compared with ox-LDL 72-h group(P<0.05). The Wnt/ β-catenin signaling pathway may play an important role in transformation of valvular myofibroblasts to the osteoblast-like phenotype.
文摘Objective: To investigate the molecular mechanisms and effective target ponits of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) receptors in macrophages in mice. Methods: Macrophages in mice were treated with curcumin, which was purified from the ethanolly extraction of Rhizoma Curcumae Longae for 24 h. The LDL receptors expressed in the macrophages were determined by enzyme-linked immunosorbent assay (ELISA) and assay of DiI labeled LDL uptake by flow cytometer. Results: It was found for the first time that 10 μmol/L-50 μmol/L curcumin could obviously up-regulate the expression of LDL receptor in macrophages in mice, and a dose-effect relationship was demonstrated. Conclusion: One of the lipid-lowering mechanisms of traditional Chinese medicine, Rhizoma Curcumae Longae, was completed by the effect of curcumin through the up-regulation of the expression of LDL receptor.
文摘A novel low-density lipoprotein adsorbent was prepared simply by directly phosphonating porous cellulose beads. Tests in vitro demonstrated that this adsorbent showed quite good adsorption performance for selective removal of low-density lipoprotein from human plasma. The effects of preparation conditions on the lipoprotein sorption properties of the resulted adsorbent were investigated. The adsorption dynamics was also examined.
文摘Summary:In the present study, we examined the regulation of the expression and function of ABCA1 by modified LDL (ox-LDL) in vitro. After incubation with apoA-I for 24 h, RAW264.7 cells effluxed 37.65 % cholesterol loaded by acetyl LDL (ac-LDL), and 9.78 % cholesterol in ox-LDL group. The level of ABCA1 mRNA increased about three times either when cells were incubated with 100 μg /mL ac-LDL or with 100 μg /mL ox-LDL. However, the level of ABCA1 protein rose by 1.57 times in ac-LDL group and 1.26 times in ox-LDL group. These results demonstrated that ox-LDL had different effect on the expression and function of ABCA1, ox-LDL might decrease the cholesterol efflux mediated by ABCA1 through other unknown mechanisms.
文摘The American Diabetes Association (ADA) 2013 guidelines state that a reasonable hemoglobin A1c goal for many nonpregnant adults with diabetes is less than 7.0% a hemoglobin A1c level of less than 6.5% may be considered in adults with short duration of diabetes, long life expectancy, and no significant cardiovascular disease if this can be achieved without significant hypoglycemia or other adverse effects of treatment. A hemoglobin A1c level less than 8.0% may be appropriate for patients with a history of severe hypoglycemia, limited life expectancy, advanced macrovascular and microvascular complications, extensive comorbidities, and long-standing diabetes in whom the hemoglobin A1c goal is difficult to attain despite multiple glucoselowering drugs including insulin. The ADA 2013 guidelines recommend that the systolic blood pressure in most diabetics with hypertension should be reduced to less than 140 mmHg. These guidelines also recommend use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in the treatment of hypertension in diabetics unless they are pregnant. Diabetics at high risk for cardiovascular events should have theirserum low-density lipoprotein (LDL) cholesterol lowered to less than 70 mg/dL with statins. Lower-risk diabetics should have their serum LDL cholesterol reduced to less than 100 mg/dL. Combination therapy of a statin with either a fibrate or niacin has not been shown to provide additional cardiovascular benefit above statin therapy alone and is not recommended. Hypertriglyceridemia should be treated with dietary and lifestyle changes. Severe hypertriglyceridemia should be treated with drug therapy to reduce the risk of acute pancreatitis.
基金This project was supported by a grant from National Natu-ral Sciences Foundation of China (No .30300134)
文摘To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively, the ldl-A7 cell lines were transfected and two cell lines expressing VLDL-R were obtained: one stably expressing the VLDLR with the O-linked sugar region (type I VLDLR) and the other without the O-linked sugar region (type II VLDLR). In the study on binding of VLDLR to their nuclein labeled natural ligands (VLDL and β-VLDL), it was found that surface binding of 125I-VLDL or 125I-β-VLDL of ldl-A7 cells transfected with type I VLDLR recombinant (ldl-A7-VRI) was more higher than that of ldl-A7 cells transfected with type II VLDLR recombinant (ldl-A7-VRII). After being incubated with VLDL for different time, the contents of triglyceride and total cholesterol in cells were mensurated, and the formation of foam cells and accumulation of lipid in cells was observed by oil-red O staining. The results showed that the contents of triglyceride and total cholesterol in ldl-A7-VR I were much higher than those in ldl-A7-VR II, and ldl-A7-VR I could transform into foam cells notably. It was suggested that type I VLDLR binds with relative higher affinity to VLDL and β-VLDL, and internalizes much more lipoprotein into cells. As a result, we can conclude that type I VLDLR plays a more important role in lipoprotein metabolism and foam cells formation than type II VLDLR.
基金Supported by Programa para el Desarrollo Profesional Docente(PRODEP)to Gonzalez-Aldaco K,No.UDG-PTC-1422Consejo Nacional de Ciencia y Tecnología(CONACYT)to Panduro A,No.2017-01-5254
文摘BACKGROUND Cholesterol is related to improvements in the rate of sustained virological response and a robust immune response against the hepatitis C virus(HCV).APOE gene polymorphisms regulate cholesterol levels modifying the course of the HCV infection.The relationship between cholesterol,APOE alleles,and the outcome of HCV infection has not been evaluated in the admixed population of Mexico.AIM To investigate the role of APOE-ε2,-ε3,and-ε4 alleles and the metabolic profile in the outcome of HCV infection.METHODS A total of 299 treatment-na?ve HCV patients were included in this retrospective study.Patients were stratified in chronic hepatitis C(CHC)(n=206)and spontaneous clearance(SC)(n=93).A clinical record was registered.Biochemical tests were assessed by dry chemistry assay.APOE genotypes were determined using a Real-Time polymerase chain reaction assay.RESULTS Total cholesterol,low-density lipoprotein cholesterol(LDL-c),triglycerides,and hypercholesterolemia were higher in SC than CHC patients as well as the frequency of the APOEε4 allele(12.4%vs 7.3%).SC patients were overweight(54.8%).Theε4 allele was associated with SC(OR=0.55,95%CI:0.31-0.98,P=0.042)and mild fibrosis(F1-F2)in CHC patients(OR 0.091,95%CI 0.01-0.75,P=0.020).LDL-c≥101.5 mg/dL(OR=0.20,95%CI:0.10-0.41,P<0.001)and BMI≥26.6 kg/m2(OR=0.37,95%CI:0.18-0.76,P<0.001)were associated with SC status;while ALT≥50.5 IU/L was negatively associated(OR=5.67,95%CI:2.69-11.97,P<0.001).CONCLUSION In SC patients,the APOEε4 allele and LDL-c conferred a protective effect in the course of the HCV infection in the context of excess body weight.
